This project will augment ongoing measurements of aerosols and co-pollutants at the Pico Mountain Atmospheric Observatory in the central North Atlantic, at 2.2 kilometers above sea level on Pico Island in the Azores archipelago. The Observatory resides well above the marine boundary layer and receives air characteristic of the lower free troposphere during most times. The site has been found to be highly valuable for studying continental outflow that has not been affected by the ocean and local emissions since leaving the continent up to three weeks earlier. Consequently, this site is an ideal location to investigate pollution transport events originating from human activities in North America, from fires in the boreal regions, and occasionally from Saharan dust intrusions. Previous measurements and simulations of dispersion and chemical transport have examined the impacts of outflow from North America on tropospheric ozone and its precursors over the North Atlantic Ocean. In this project, new measurements will be added to the parameters presently measured to address the radiative properties of aerosols and its co-pollutants. These data will allow study of the optical properties and composition of long-range transported aerosols. Radiative forcing of light-absorbing carbon and its co-pollutants in air masses undergoing long-range transport and monitored at the Pico Observatory will be determined by a combination of 3-dimensional chemistry-transport and chemistry-climate models and dispersion modeling.
The results will contribute to understanding of aerosol chemical, physical and radiative properties with respect to long-range transport and aerosol aging. It will provide the first detailed multi-year chemical and optical measurements of North Atlantic free tropospheric aerosol. A climatology of the frequency and occurrence of long-range transported light absorbing aerosol at Pico Mountain will be developed. The observations, modeled chemical transport, and radiative forcing simulations will provide a foundation for further research on global light-absorbing aerosol properties and on its distribution, for improved remote sensing data interpretations. The project will bring together investigators from three U.S. universities and one Portuguese university. Two participants from the Teachers Education Division at Michigan Technological University will be involved. These student teachers will participate in the field research at Pico and develop new education plans for high school students. Further outreach will be possible with a new Pico Mountain research web page and a display in the Pico Mountain National Park visitor center.